#include <bits/stdc++.h>
using namespace std;

#include <bits/extc++.h>
using namespace __gnu_pbds;

using llt = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;

int N;
string S;

void proc(){
    for(int i=0;i<N;i+=2){
        if(islower(S[i])) S[i] = toupper(S[i]);
        else if(isupper(S[i])) S[i] = tolower(S[i]);
    }
    cout << S << endl;
}

int main(){
#ifndef ONLINE_JUDGE
    freopen("z.txt", "r", stdin);
#endif
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(0);
    int nofkase = 1;
    // cin >> nofkase;
    while(nofkase--){
        cin >> N >> S;
        proc();
    }
    return 0;
}